The nurse being investigated in connection to missing Colorado mom Kelsey Berreth's disappearance will reportedly plead guilty to at least one count this week.

It's not clear what Krystal Lee, 32, will possibly plead guilty to, according to ABC News, but the plea reportedly comes as part of a deal with prosecutors in the case. Lee is set to appear in court on Friday.

It's been rumored that Lee reportedly helped dispose of a cellphone belonging to Berreth, who was last seen arriving at a Colorado Safeway supermarket with her 1-year-old daughter, Kaylee, about 12:30 p.m. on Thanksgiving. Though authorities strongly believe she is dead, her body has not yet been found.

Berreth's fiance, Patrick Frazee, is charged in her murder.

Lee lives about 30 minutes from where the mother's cellphone last pinged in Idaho, three days after and hundreds of miles way from she was last seen.

A 32-year-old divorced mother of two, Lee's relationship to Frazee is unclear, but they reportedly became romantically involved after meeting at a rodeo. Police have not confirmed that they are investigating Lee and the district attorney's office would not comment on a potential plea deal, according to ABC News.

"This case is under seal," Lee Richards, a spokeswoman for Colorado's 4th Judicial District Attorney's Office, told the outlet.

Frazee is being held without bond at the Teller County Jail in Divide. He has not yet entered a plea to the charges filed against him, which include two counts of murder and three counts of solicitation to commit murder. A preliminary hearing is now scheduled for February.

A friend of Berreth's told CBS News last month that Frazee was always "mad about something."

"The moment that I found out that she had been missing, the first words that came out of my mouth were, 'He did something to her,'" Ashley Cogburn said.

Berreth's parents, Cheryl and Darrell, have also filed a wrongful death lawsuit Friday, seeking unspecified damages against Frazee.